Two percent of Harvard’s library collection circulates every year. A high percentage of the works that are checked out are the same as the books that were checked out last year. This fact can cause reflexive tsk-tsking among librarians. But — with some heavy qualifications to come — this is at it should be. The existence of a Long Tail is not a sign of failure or waste. To see this, consider what it would be like if there were no Long Tail.

Harvard’s 73 libraries have 16 million items [source]. There are 21,000 students and 2,400 faculty [source]. If we guess that half of the library items are available for check-out, which seems conservative, that would mean that 160,000 different items are checked out every year. If there were no Long Tail, then no book would be checked out more than any other. In that case, it would take the Harvard community an even fifty years before anyone would have read the same book as anyone else. And a university community in which across two generations no one has read the same book as anyone else is not a university community.

I know my assumptions are off. For example, I’m not counting books that are read in the library and not checked out. But my point remains: we want our libraries to have nice long tails. Library long tails are where culture is preserved and discovery occurs.

And, having said that, it is perfectly reasonable to work to lower the difference between the Fat Head and the Long Tail, and it is always desirable to help people to find the treasures in the Long Tail. Which means this post is arguing against a straw man: no one actually wants to get rid of the Long Tail. But I prefer to put it that this post argues against a reflex of thought I find within myself and have encountered in others. The Long Tail is a requirement for the development of culture and ideas, and at the same time, we should always help users to bring riches out of the Long Tail